The present invention relates to an axial strap support for a cryostat containing a superconducting magnetic resonance imaging magnet.
A cryostat is a containment vessel designed to thermally isolate its interior from exterior ambient temperature conditions. To achieve the desired degree of thermal isolation, multiple nested vessels may be employed with each vessel functioning at one of a sequence of temperatures, with the interior temperature of the innermost vessel being the coldest. The inner vessels need to be supported spaced apart from one another with sufficient rigidity to withstand shipping loads yet have as few physical connections between the interior vessels and the external vessels to minimize heat leak.
One approach for an axial positioner uses three concentric cylinders with one end of the inner positioner cylinder connected to an inner vessel and one end of the outer positioner cylinder connected to the outer vessel. The intermediate positioner cylinder connected the other ends of the inner and outer cylinder ends increasing the effective length of the thermal path between the two vessels. This approach has the drawbacks of being composed of a large number of parts, the bonded joints connecting the positioner cylinders together are process sensitive and finally it is not very rugged or forgiving of assembly errors or tolerance stackings.
It is an object of the present invention to provide an axial strap suspension which is sufficiently strong to withstand shipping loads and has few parts.
It is another object of the present invention to provide an axial strap suspension which accommodates manufacturing tolerance stackup error and provides improved fatigue loading cycle performance.